/*
 * acm1405.c
 *
 *  Created on: 24 Mar 2010
 *      Author: xuxu
 */

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int main()
{
	char num[26];
	int len;
	int n;
	char c;
	int count;
	while(scanf("%d",&n)&&n)
	{
		scanf("%c",&c);
		len=0;
		count=0;
		memset(num,'0',sizeof(num));
		while(scanf("%c",&c)&&c!='\n')
		{
			if('0'==num[c-'A'])
			{
				num[c-'A']=c;
				len++;
				if(len>n)
					count++;
			}
			else
			{
				num[c-'A']='0';
				len--;
			}
		}
		if(count)
			printf("%d customer(s) walked away.\n",count);
		else
			printf("All customers tanned successfully.\n");
	}
	return  0;
}
